Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[sfrench/cifs-2.6.git] / arch / s390 / include / asm / spinlock.h
index d97175e16d9b48aaca6857ad05433fcfc0edab6f..0a29588aa00b64e21ffba5b31d77be94982f47a0 100644 (file)
@@ -14,6 +14,7 @@
 #include <asm/atomic_ops.h>
 #include <asm/barrier.h>
 #include <asm/processor.h>
+#include <asm/alternative.h>
 
 #define SPINLOCK_LOCKVAL (S390_lowcore.spinlock_lockval)
 
@@ -36,21 +37,16 @@ bool arch_vcpu_is_preempted(int cpu);
  * (the type definitions are in asm/spinlock_types.h)
  */
 
-void arch_lock_relax(int cpu);
+void arch_spin_relax(arch_spinlock_t *lock);
+#define arch_spin_relax        arch_spin_relax
 
 void arch_spin_lock_wait(arch_spinlock_t *);
 int arch_spin_trylock_retry(arch_spinlock_t *);
-void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags);
-
-static inline void arch_spin_relax(arch_spinlock_t *lock)
-{
-       arch_lock_relax(lock->lock);
-}
-#define arch_spin_relax                arch_spin_relax
+void arch_spin_lock_setup(int cpu);
 
 static inline u32 arch_spin_lockval(int cpu)
 {
-       return ~cpu;
+       return cpu + 1;
 }
 
 static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
@@ -66,8 +62,7 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lp)
 static inline int arch_spin_trylock_once(arch_spinlock_t *lp)
 {
        barrier();
-       return likely(arch_spin_value_unlocked(*lp) &&
-                     __atomic_cmpxchg_bool(&lp->lock, 0, SPINLOCK_LOCKVAL));
+       return likely(__atomic_cmpxchg_bool(&lp->lock, 0, SPINLOCK_LOCKVAL));
 }
 
 static inline void arch_spin_lock(arch_spinlock_t *lp)
@@ -80,7 +75,7 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *lp,
                                        unsigned long flags)
 {
        if (!arch_spin_trylock_once(lp))
-               arch_spin_lock_wait_flags(lp, flags);
+               arch_spin_lock_wait(lp);
 }
 #define arch_spin_lock_flags   arch_spin_lock_flags
 
@@ -95,11 +90,10 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp)
 {
        typecheck(int, lp->lock);
        asm volatile(
-#ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
-               "       .long   0xb2fa0070\n"   /* NIAI 7 */
-#endif
-               "       st      %1,%0\n"
-               : "=Q" (lp->lock) : "d" (0) : "cc", "memory");
+               ALTERNATIVE("", ".long 0xb2fa0070", 49) /* NIAI 7 */
+               "       sth     %1,%0\n"
+               : "=Q" (((unsigned short *) &lp->lock)[1])
+               : "d" (0) : "cc", "memory");
 }
 
 /*
@@ -113,155 +107,53 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp)
  * read-locks.
  */
 
-extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
-extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
-
-static inline int arch_read_trylock_once(arch_rwlock_t *rw)
-{
-       int old = READ_ONCE(rw->lock);
-       return likely(old >= 0 &&
-                     __atomic_cmpxchg_bool(&rw->lock, old, old + 1));
-}
-
-static inline int arch_write_trylock_once(arch_rwlock_t *rw)
-{
-       int old = READ_ONCE(rw->lock);
-       return likely(old == 0 &&
-                     __atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000));
-}
-
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+#define arch_read_relax(rw) barrier()
+#define arch_write_relax(rw) barrier()
 
-#define __RAW_OP_OR    "lao"
-#define __RAW_OP_AND   "lan"
-#define __RAW_OP_ADD   "laa"
-
-#define __RAW_LOCK(ptr, op_val, op_string)             \
-({                                                     \
-       int old_val;                                    \
-                                                       \
-       typecheck(int *, ptr);                          \
-       asm volatile(                                   \
-               op_string "     %0,%2,%1\n"             \
-               "bcr    14,0\n"                         \
-               : "=d" (old_val), "+Q" (*ptr)           \
-               : "d" (op_val)                          \
-               : "cc", "memory");                      \
-       old_val;                                        \
-})
-
-#define __RAW_UNLOCK(ptr, op_val, op_string)           \
-({                                                     \
-       int old_val;                                    \
-                                                       \
-       typecheck(int *, ptr);                          \
-       asm volatile(                                   \
-               op_string "     %0,%2,%1\n"             \
-               : "=d" (old_val), "+Q" (*ptr)           \
-               : "d" (op_val)                          \
-               : "cc", "memory");                      \
-       old_val;                                        \
-})
-
-extern void _raw_read_lock_wait(arch_rwlock_t *lp);
-extern void _raw_write_lock_wait(arch_rwlock_t *lp, int prev);
+void arch_read_lock_wait(arch_rwlock_t *lp);
+void arch_write_lock_wait(arch_rwlock_t *lp);
 
 static inline void arch_read_lock(arch_rwlock_t *rw)
 {
        int old;
 
-       old = __RAW_LOCK(&rw->lock, 1, __RAW_OP_ADD);
-       if (old 0)
-               _raw_read_lock_wait(rw);
+       old = __atomic_add(1, &rw->cnts);
+       if (old & 0xffff0000)
+               arch_read_lock_wait(rw);
 }
 
 static inline void arch_read_unlock(arch_rwlock_t *rw)
 {
-       __RAW_UNLOCK(&rw->lock, -1, __RAW_OP_ADD);
+       __atomic_add_const_barrier(-1, &rw->cnts);
 }
 
 static inline void arch_write_lock(arch_rwlock_t *rw)
 {
-       int old;
-
-       old = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
-       if (old != 0)
-               _raw_write_lock_wait(rw, old);
-       rw->owner = SPINLOCK_LOCKVAL;
+       if (!__atomic_cmpxchg_bool(&rw->cnts, 0, 0x30000))
+               arch_write_lock_wait(rw);
 }
 
 static inline void arch_write_unlock(arch_rwlock_t *rw)
 {
-       rw->owner = 0;
-       __RAW_UNLOCK(&rw->lock, 0x7fffffff, __RAW_OP_AND);
+       __atomic_add_barrier(-0x30000, &rw->cnts);
 }
 
-#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
-
-extern void _raw_read_lock_wait(arch_rwlock_t *lp);
-extern void _raw_write_lock_wait(arch_rwlock_t *lp);
 
-static inline void arch_read_lock(arch_rwlock_t *rw)
-{
-       if (!arch_read_trylock_once(rw))
-               _raw_read_lock_wait(rw);
-}
-
-static inline void arch_read_unlock(arch_rwlock_t *rw)
+static inline int arch_read_trylock(arch_rwlock_t *rw)
 {
        int old;
 
-       do {
-               old = READ_ONCE(rw->lock);
-       } while (!__atomic_cmpxchg_bool(&rw->lock, old, old - 1));
-}
-
-static inline void arch_write_lock(arch_rwlock_t *rw)
-{
-       if (!arch_write_trylock_once(rw))
-               _raw_write_lock_wait(rw);
-       rw->owner = SPINLOCK_LOCKVAL;
-}
-
-static inline void arch_write_unlock(arch_rwlock_t *rw)
-{
-       typecheck(int, rw->lock);
-
-       rw->owner = 0;
-       asm volatile(
-               "st     %1,%0\n"
-               : "+Q" (rw->lock)
-               : "d" (0)
-               : "cc", "memory");
-}
-
-#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
-
-static inline int arch_read_trylock(arch_rwlock_t *rw)
-{
-       if (!arch_read_trylock_once(rw))
-               return _raw_read_trylock_retry(rw);
-       return 1;
+       old = READ_ONCE(rw->cnts);
+       return (!(old & 0xffff0000) &&
+               __atomic_cmpxchg_bool(&rw->cnts, old, old + 1));
 }
 
 static inline int arch_write_trylock(arch_rwlock_t *rw)
 {
-       if (!arch_write_trylock_once(rw) && !_raw_write_trylock_retry(rw))
-               return 0;
-       rw->owner = SPINLOCK_LOCKVAL;
-       return 1;
-}
-
-static inline void arch_read_relax(arch_rwlock_t *rw)
-{
-       arch_lock_relax(rw->owner);
-}
-#define arch_read_relax                arch_read_relax
+       int old;
 
-static inline void arch_write_relax(arch_rwlock_t *rw)
-{
-       arch_lock_relax(rw->owner);
+       old = READ_ONCE(rw->cnts);
+       return !old && __atomic_cmpxchg_bool(&rw->cnts, 0, 0x30000);
 }
-#define arch_write_relax       arch_write_relax
 
 #endif /* __ASM_SPINLOCK_H */